The Object Tool "Import SemiGlobals" has check boxes for "fix package references" and "add name prefix", yet checking both these boxes when importing a semiglobal does NOT change the semiglobal's Group ID! I imported a semiglobal and modified it, and because it retained the original Maxis Group ID, it overrode everything in the game that used that semi.

I had to manually extract the semiglobals from the package, then edit them in notepad to change the Group ID's to FFFFFFFF, then re-import them into SimPE. The importer should automatically change the Group ID to FFFFFFFF, wouldn't you say? Otherwise the only reason to import semiglobals is to make a global hack.

You can modify it in Simpe, also Fix Integrity usually changes it to xFFFFFF